Order fulfillment is typically performed in a large warehouse filled with products to be shipped to customers who have placed their orders over the internet for home delivery. In some operations, humans may manually fulfill orders by traversing the warehouse to retrieve the items in the orders. In other operations, robots may be used to perform the item retrieval functions in place of humans, or robots may be used to assist humans in item retrieval in both cases in order to increase productivity and efficiency.
Fulfilling such orders in a timely, accurate and efficient manner is logistically challenging to say the least. Clicking the “check out” button in a virtual shopping cart creates an “order.” The order includes a listing of items that are to be shipped to a particular address. The process of “fulfillment” involves physically taking or “picking” these items from a large warehouse, packing them, and shipping them to the designated address. An important goal of the order-fulfillment process is thus to ship as many items in as short a time as possible.
A warehouse management system (WMS) is a software application that supports the day-to-day operations in an order fulfillment warehouse like the one described above, which may utilize humans and/or robots to increase efficiency and productivity of the operation. WMS programs enable centralized management of tasks, such as tracking inventory levels and stock locations. Warehouse management systems also support or direct all of the major and many minor warehouse tasks such as receiving, inspection and acceptance, put-away, internal replenishment to picking positions, picking, packing, order assembly on the shipping dock, documentation, and shipping (loading onto carrier vehicles).
The WMS typically receives orders from the overlying host system, usually an ERP system. For order fulfillment via. E-Commerce orders, as soon as a customer places an order online, the information is passed along via the host computer (an ERP system) to the WMS. All necessary steps to manage this order (e.g. pick the ordered items etc.) are then processed within the WMS. Afterwards information is sent back to the business host computer to support financial transactions, advance shipping notifications to customers, inventory management, etc.
As the orders from the WMS accrue they are held in an order queue and distributed to the humans or robots to execute the orders within the warehouse. The orders may be taken in sequence from the order queue in the order they arrived and assigned to humans and/or robots to execute the orders. The orders may also be arranged in the order queue and assigned according to service level requirements defined in the customer contracts or based on customer shipping requirements. While these systems have become quite sophisticated, there still exists a need to improve efficiency and productivity in the order queuing and assignment process.